Perforation forming machine, sheet processing apparatus, and image forming system

Abstract

A perforation forming machine including, a biasing mechanism that constantly biases a cutter toward a receiving base; and a cam configured to form a state in which the cutter can be pressed against the receiving base by a biasing force and a state in which the cutter is separated from the receiving base against the biasing force. A presser is disposed in a state in which the perforating blade is separated from the receiving base via the sheet and the presser is configured so as to be able to press the cutter toward the receiving base. In a case in which the perforating blade is separated from the receiving base via the sheet, the cam is made to abut against the presser to displace the cutter toward the receiving base, and the perforating blade is pressed down to a height at which the perforating blade penetrates the sheet.

What is claimed is: 
     
         1 . A perforation forming machine that includes a processing machine capable of forming a perforation on a sheet conveyed between a cutter including a perforating blade, and a receiving base that receives the cutter, the perforation forming machine comprising:
 a biasing mechanism that constantly biases the cutter toward the receiving base; and   a cam configured to form a state in which the cutter can be pressed against the receiving base by a biasing force of the biasing mechanism and a state in which the cutter is separated from the receiving base against the biasing force of the biasing mechanism,   wherein a presser that is disposed within a moving route of the cam in a state in which the perforating blade is separated from the receiving base via the sheet and the presser is configured so as to be able to press the cutter toward the receiving base, and   wherein, in a case in which the perforating blade is separated from the receiving base via the sheet, the cam is made to abut against the presser to displace the cutter toward the receiving base, and the perforating blade is pressed down to a height at which the perforating blade penetrates the sheet.   
     
     
         2 . The perforation forming machine according to  claim 1 ,
 further comprising a holding member that holds the cutter and that includes the presser,   wherein the biasing mechanism constantly biases the cutter toward the receiving base by biasing the holding member by a biasing member.   
     
     
         3 . The perforation forming machine according to  claim 2 , wherein the holding member is rotatable about a fulcrum disposed at a position separated from a part holding the cutter, and the presser is disposed on a side opposite to the fulcrum with respect to the part of the holding member holding the cutter. 
     
     
         4 . The perforation forming machine according to  claim 2 , wherein the cutter is a rotary type. 
     
     
         5 . The perforation forming machine according to  claim 4 , wherein the cutter includes an annular rubber roller that is coaxial with and adjacent to the cutter, and the cutter is rotated by causing the sheet conveyed between the cutter and the receiving base to abut on the rubber roller. 
     
     
         6 . The perforation forming machine according to  claim 2 , wherein the cutter is a guillotine type. 
     
     
         7 . The perforation forming machine according to  claim 2 , wherein a formation direction of the perforation is a direction parallel to a conveyance direction of the sheet. 
     
     
         8 . The perforation forming machine according to  claim 2 , wherein a formation direction of the perforation is a direction orthogonal to a conveyance direction of the sheet. 
     
     
         9 . A sheet processing apparatus comprising:
 the perforation forming machine according to  claim 1  which is detachably attached to the sheet processing apparatus as one of functional units.   
     
     
         10 . An image forming system comprising:
 an image forming apparatus that forms an image on a sheet, and   the sheet processing apparatus according to claim  9  that forms the perforation on the sheet on which the image has been formed by the image forming apparatus.